Over labelling of IMP following unblinding

Dear All,
I work for a double blinded clinical study and the unblinded data has recently been reviewed for the first time since the beginning of the trial. The IMP has been seen to have a positive effect. Therefore, the trial steering committee has agreed to give all the participants the option of being unblinded. An amendment to the study protocol will soon be submitted to the competent authorities. I have a question regarding the labelling of the IMP: following the unblinding, the participants found to be on the active drug will continue with the trial treatment and take their current pot of trial medication until finished. Further supply for these participants will be labelled as 'active' rather than 'active or placebo'. Some supplies have already been shipped to the study centres and are ready to be dispensed. Can an over-labelling activity be done in hospital pharmacies? What would be the procedure to follow for an over-labelling of these supplies? One of my colleague contacted the MHRA helpline and she was told that local pharmacist would be able to change the label and no authorisation is needed because there is an exemption for hospital pharmacies. She was also told that the best thing would be for pharmacists to blackout the placebo part of the label rather than overlabel as this would be safest. We requested to have these recommendations in writting but we haven't received any email yet. Please, I would like your opinion on this topic. Any advice is greatly appreciated.